Solutions of polytrifluoro-chlorethylene



United States Patent SOLUTIONS OF POLYTRIFLUORO- CHLORETHYLENE OttoFuchs, Frankfurt am Main Hochst, Anton Staller, Frankfurt am MainSindliugen, and Rudolf Schiitf, Frankfurt am Main Hochst, Germany,assignors to Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius& Briining, Frankfurt am Main Hochst, Germany, a company of Germany NoDrawing. Application June 8, 1953 Serial No. 360,385

Claims priority, application Germany June 10, 1952 7 Claims. (Cl.26030.2)

As compared with other synthetic substances of high molecular weight,polymerized trifluorochlorethylene has a very high softening point (240C. or higher) and its solubility in inorganic and organic substances isvery low. Although both properties are of great advantage from the pointof view of the practical utility of the polymer, they make it difficultto shape the polymer, for instance, for producing foils, fibers and thelike. A further disadvantage is that the polymer separates out of itssolutions in the solvents hitherto known at temperatures above 100 C.when the solutions are cooled, and this is especially undesirable inproducing coatings of the polymer on solid supports. For this reasonthere is a great demand for solvents of which the boiling point is nottoo high and which also permit the solutions to be cooled as far aspossible below about 110 C. without the occurrence of demixingaccompanied by separation of the polymer.

Now we have found that the above requirements are fulfilled by solutionsof polymerized trifluoro-chlorethylone inl:1:2:2-tetrafiuoro-3:3:4:4-tetrachlorocyclobutane (boiling at 132 C.)alone or in admixture with another organic compound viz. an aliphatic,monocyclic or bicyclic aromatic, monocyclic heterocyclic or monocyclicor bicyclic hydroaromatic compound containing l-4 substituents, forexample, alkyl groups containing 1-3 carbon atoms, alkoxy groupscontaining 1-3 carbon atoms, chlorine atoms or -CF,, groups.

In the organic compound to be used in admixture with the 1:l:2:2tetrafluoro -3 3 :4:4-tetrachlorocyclobutane the aforesaid substituentsmay all be the same or they may be different in a single compound.

The polymer may be dissolved in the solvent or solvent mixture at atemperature above about 80 C. The exact temperature of dissolution canbe determined in any particular case by a simple test.

The difference between the solvent mixtures of the present invention andother solvent mixtures is illustrated by the following:

If, for instance, the polymer is dissolved in a mixture of para-xyleneand ortho-chlorobenzotrifluoride (the latter being capable alone ofdissolving the polymer) the polymer separates out at 115 C. A solutionof the polymer in a mixture of 1:2:3-trifiuoropentachloropropane (whichis itself a solvent for polymerized trifluorochlorethylene) and xyleneis stable only at temperatures not lower than 105 C. If, however, amixture of 1:1:2z2 tetrafluoro 3:3:4:4 tetrachlorocyclobutane andpara-xylene is used as solvent, the solution of the polymer becomesnon-homogeneous only at a temperature of 75 C. or lower.

In the following table are given examples of solutions in accordancewith the invention. The polymerized trifluoro- ICC chlorethylene servingas starting material has a molecular weight of 75,000 according to NSTand osmotic data given by Kaufmann and Muthana in I. Polymer Science, 6,page 251 (1951).

The concentration of the polymer in the solutions of the examples givenin the table ranges from 5 to 11 percent. The solvents are alsoeffective at lower or higher concentrations of the polymer in thesolutions. For the preparation of the solvent mixture 1570 percent, andadvantageously 2060 percent, of the said solvents should be added to thel:1:2:2-tetrafluoro-3z3:4:4-tetrachlorocyclobutane.

Composition of the solution (percentage by weight) Temperature ofcommence- Nature of the ment of sepadditive 121:2:2-tetraoration of theAdditive fluoro-3:3:4:4- Polymer polymer, C.

tetrachlorocyclobutane 89 11 100 23. 5 71 5. 5 76 22 67 11 83 benzenel3. 0 79 8.0 para-eymene 22. 5 67. 5 10 91 orthophloro-toluene. 23. 5 715. 5 75 D 22 67 11 75 ortho dichloro benzene 22. 5 67. 5 10 762'methyl-pyridine. 19 76 5 64 2 :4:6-trimethyl-pyridine 3B 57 5 66 57 385 anisole 38 57 5 80 hydroquinone dimethyl ether 4O 55 5 75 resoreinoldimethyl ether 40 55 5 8 1:2:3-trifiuoro-pentaehloropropane 23. 5 71 5.5 66 1:112:2-tetrachlorethane 25. 0 68 7. 0 83 perchlorethylenen... 2271 7 80 naphthalene 23. 5 71 5. 5 tetrahydronaphthalene 23. 5 71 5. 5 86dioxane 13.0 79 8.0 78 lzrdimethoxy-lethoxy-ethane O C 2H5 47. 5 47. 5 575 H3C' O (O CH phenetole 13.0 79 8.0 84 ethyl-benzene 13. 0 79 8. 0 82Among the compounds added those which contain alkyl groups, alkoxygroups, for example, methoxy groups, chlorine atoms or -CF groups, areespecially suitable because with these substituents the tem erature ofdissolution is lower by 3040 degrees centigrade, more highlyconcentrated solutions can be prepared, and finally a smaller proportionof l:l:2:2-tetrafluoro-3:3:4:4-tetrachlorocyclobutane suflices toproduce the same result, than if those substituents were absent.

We claim:

1. Solution of from substantially 5 to 11% polytrifluorochlorethylene ina mixture of from 19 to 80% of 1 l :2 2-tetrafiuoro-3 3 :4:4-tetrachlorocyclobutane with from substantially 15 to 70% of anotherorganic compound selected from the group consisting of benzene,substituted benzene, dioxane, naphthalene, tetrahydronaphthalene,1:2:3-trifiuoropentachloropropane, 1:1:212- tetrachlorethane,1:l-dimethoxy-l-ethoxy-ethane, perchlorethylene, 2-methyl-pyridine, and2:4:6-trimethylpyridine, wherein said substituted benzene compound maycontain from 1 to 4 substituents selected from the group consisting ofchloro, alkyl of l to 3 carbon atoms and alkoxy of 1 to 3 carbon atoms,and wherein said substituted benzene compound is free from othersubstituents.

2. Solution according to claim 1, wherein the polytrifiuorochlorethyleneis in a mixture of 1:1:222-tetrafluoro-3:3:4:4-tetrachlorocyclobutanewith toluene.

3. Solution according to claim 1, wherein the polytrifluorochlorethyleneis in a mixture of 1:1:2z2-tetrafiuoro-3:3:4:4-tetrachlorocyclobutanewith para-xylene.

4. Solution according to claim 1, wherein the polytrifiuorochlorethyleneis in a mixture of 121:2:2-tet12tfluoro 323:4:4 tetrachloroeyclobutanewith Z-methylpyridine.

5. Solution according to claim 1, wherein the polytrifiuorochlorethyleneis in a mixture of 1:1:2:2-tetrafluoro 3:3 :4:4 tetraehlorocyclobutanewith perchlorethylene.

6. Solution according to claim I, wherein the polytrifluorochlorethyleneis in a mixture of 1:l:2:2-tctrafluo1'o-3 :3 :4:4-tetraehlorocyclobutanewith dioxanc.

7. Solution of polytrifiuorochlorethylene in 1:1:2:2 tetrnfiuoro-3 :34:4'tetrachlorocyclobutane.

References Cited in the file of this patent UNITED STATES PATENTS2,656,330 Sprung Oct. 20, 1953

1. SOLUTION OF FROM SUBSTANTIALLY 5 TO 11% POLYTRIFLUOROCHLOROETHYLENEIN A MIXTURE OF FROM 19 TO 80% OF1:1:2:2-TETRAFLUORO-3:3:4:4-TETRACHLOROCYCLOBUTANE WITH FROMSUBSTANTIALLY 15 TO 70% OF ANOTHER ORGANIC COMPOUND SELECTED FROM THEGROUP CONSISTING OF BENZENE, SUBSTITUTED BENZENE, DIOXANE, NAPHTHALENE,TETRAHYDRONAPHTHALENE, 1:2:3-TRIFLUOROPENTACHLOROPROPANE,1:1:2:2TETRACHLOROETHANE, 1:1-DIMETHOXY-1-ETHOXY-ETHANE, CLORETHYLENE,2-METHYL-PYURIDINE, AND 2:4:6-TRIMETHYLPYRIDINE, WHEREIN SAIDSUBSTITUTED BENZENE COMPOUND MAY CONTAIN FROM 1 TO 4 SUBSTITUENTSSELECTED FROM THE GROUP CONSISTING OF CHLORO, ALKYL OF 1 TO 3 CARBONATOMS AND ALKOXY OF 1 TO 3 CARBON ATOMS, AND WHEREIN SAID SUBSTITUTEDBENZENE COMPOUND IS FREE FROM OTHER SUBSTITUENTS.